Why do we not feel pain when a mosquito bites us. Please explain the whole scientific theory behind this.

               Dear student
mosquito have surprisingly small mouthparts, making it hard to feel them when they bite us. we also can't feel the legs due to the low weight and small leg surface area touching the bitten subject. after the bite, the mosquito's salive will couse an itch which is the moment people will feel the bite
           Regards